- Add busy_timeout PRAGMA and MaxOpenConns(1) for SQLite stability
- Use per-test temp DB in handler tests to prevent state leaks
- Pre-allocate migrations slice (prealloc lint)
- Remove invalid linter names (wsl_v5, noinlineerr) from .golangci.yml
- Remove unused //nolint:gosec directives
- Replace context.Background() with t.Context() in tests
- Use goimports formatting for all files
- All make check passes with zero failures
- Integration tests for all API endpoints (session, state, channels, messages)
- Tests for all commands: PRIVMSG, JOIN, PART, NICK, TOPIC, QUIT, PING
- Edge cases: duplicate nick, empty/invalid inputs, malformed JSON, bad auth
- Long-poll tests: delivery on notify and timeout behavior
- DM tests: delivery to recipient, echo to sender, nonexistent user
- Ephemeral channel cleanup test
- Concurrent session creation test
- Nick broadcast to channel members test
- DB unit tests: all CRUD operations, message queue, history
- Broker unit tests: wait/notify, remove, concurrent access